Members of Libyan forces allied with the UN-backed government fire a weapon towards Islamic State militants in neighbourhood Number One in central Sirte, Libya August 28, 2016. (Photo by Ismail Zitouny/Reuters)

A member of Libyan forces allied with the UN-backed government fires a weapon towards Islamic State militants in neighbourhood Number One in central Sirte, Libya August 28, 2016. (Photo by Ismail Zitouny/Reuters)

A member of Libyan forces allied with the UN-backed government fires a weapon towards Islamic State militants in neighbourhood Number One in central Sirte, Libya August 28, 2016. (Photo by Ismail Zitouny/Reuters)

A member of Libyan forces allied with the UN-backed government fires a weapon towards Islamic State militants in neighbourhood Number One in central Sirte, Libya August 28, 2016. (Photo by Ismail Zitouny/Reuters)

A member of Libyan forces allied with the UN-backed government fires a weapon towards Islamic State militants in neighbourhood Number One in central Sirte, Libya August 28, 2016. (Photo by Ismail Zitouny/Reuters)

Libyan forces take up new positions as they prepare for next advance against Islamic State holdouts in Sirte, Libya August 29, 2016. (Photo by Ismail Zitouny/Reuters)

Libyan forces take up new positions as they prepare for next advance against Islamic State holdouts in Sirte, Libya August 29, 2016. (Photo by Ismail Zitouny/Reuters)

Libyan forces take up new positions as they prepare for next advance against Islamic State holdouts in Sirte, Libya August 29, 2016. (Photo by Ismail Zitouny/Reuters)

Libyan forces take up new positions as they prepare for next advance against Islamic State holdouts in Sirte, Libya August 29, 2016. (Photo by Ismail Zitouny/Reuters)

Libyan forces take up new positions as they prepare for next advance against Islamic State holdouts in Sirte, Libya August 29, 2016. (Photo by Ismail Zitouny/Reuters)

A member of Libyan forces prays as he prepares with his comrades for next advance against Islamic State holdouts in Sirte, Libya August 29, 2016. (Photo by Ismail Zitouny/Reuters)

Libyan forces sit atop a tank after taking up new positions as they prepare for next advance against Islamic State holdouts in Sirte, Libya August 29, 2016. (Photo by Ismail Zitouny/Reuters)

Libyan forces take up new positions as they prepare for next advance against Islamic State holdouts in Sirte, Libya August 29, 2016. (Photo by Ismail Zitouny/Reuters)

Libyan forces take up new positions as they prepare for next advance against Islamic State holdouts in Sirte, Libya August 29, 2016. (Photo by Ismail Zitouny/Reuters)

Libyan forces stand in front of a machinery they captured from Islamic State fighters as forces prepare for next advance against Islamic State holdouts in Sirte, Libya August 29, 2016. (Photo by Ismail Zitouny/Reuters)

Libyan forces sit atop a tank after taking up new positions as they prepare for next advance against Islamic State holdouts in Sirte, Libya August 29, 2016. (Photo by Ismail Zitouny/Reuters)

Donated tea and other drinks are distributed among Libyan forces as they prepare for next advance against Islamic State holdouts in Sirte, Libya August 29, 2016. (Photo by Ismail Zitouny/Reuters)

Libyan forces pray as they prepare for next advance against Islamic State holdouts in Sirte, Libya August 29, 2016. (Photo by Ismail Zitouny/Reuters)

Libyan forces ride a military vehicle as they prepare for next advance against Islamic State holdouts in Sirte, Libya August 29, 2016. (Photo by Ismail Zitouny/Reuters)